When rain falls
, it drags with it cold air (a
downdraft)
, which splashes out upon hitting the ground just as paint would if poured from a paint tin
. This splashing is the gusts of wind that blast you prior to the coming of a storm
. Of course
, that cold air is not running into empty spac
e; there is a layer of warm air hanging at ground level which is violently forced up out of the way by the rushing cold gusts
. Those two differently heated layers rub along each other
, cooling the moisture contained in the warm layer and causing it to condense
. The product of this condensation is called a shelf cloud.
The beautiful closing images from
this sequence of photographs first prompted me to nosey around this phenomenon a little.
Here are some other fine shelf cloud shots:
This last one is really quite astonishing
. The photographer—one Anthony Cornelius—must have been brav
e; i’d have run for my life from this monster.
The website he posts on is worth a
visit.
… and the last shelf is explored a little more in
this time lapse footage
. Check out how it just goes on and on to the right of the frame ther
e! Here’s an
account of the storm
, wherein the author styles it a “People Chaser Derecho”
, which among other things makes me feel like i just spun off an old Big Bopper 7
8!
